Mortising-chisel



(No Model.)

A.. P. LANTERMAN.

MURTISING GHISBL.

No. 412,275. Patented Oct. 8. 1889.

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Alli/*IN P. LANTERMAN, OF CHICAGO, lLLlNOlS.

MORTISING-CHISEL.

SPECIFICATION forming part of Letters Patent No. 412,275, dated October8, 1889.

Application filed June 11, 1889.V Serial No. 313,941. (No model.)

To all whom, it may concern:

Be it known that I, ALvIN P. LANTERMAN, a citizen of the United States,residing at Chicago, in the county of Cook and State of `the wood, andthe chisel being during such operation depressed by another appropriatemember of the machine, so that it may descend simultaneously with andfollow the work of the bit, in order to square the round hole made bythe bit.

The objects of my invention are to effectively prevent the chips fromwhirling` around with the bit during operation and to compel them topass freely and rapidly and from the point of cut up or back through thehollow chisel to the point of discharge, to avoid all danger of thechips becoming compacted within and clogging up the space between thebit andthe inner wall of the hollow chisel, to avoid retardation of therotary action of the bit, and to dispense with all necessity forlongitudinal chip -discharge slots or openings formed through the sidesof the hollow chisel, and thereby to avoid undesirably prolonging andweakening a chisel designed for cutting deep holes.

In a hollowr mort-ising-chisel characterized by my invention 4the wallof the chiselbore is provided with longitudinally-extendingserrations--that is to say, the wail is notched longitudinally in amanner to provide it with defined teeth, each of a width proportional tothe length of the two long gaps, respectively, at its opposite sides.The pitch, shape, and

number of these teeth or serrations can be varied, and l may eitherprovide the wall of the chisel-bore with teeth or sei-rationsalternating with longitudinally-extending widths or plain cylindricsurface portions, or I may sei-rate the entire surface of said wall,since in either case the serratedportion orportions will, while offeringa positive frictional resistance to the whirling or revolution of thechips with the rotating bit, offer no material frictional resistance tothe direct or straight longitudinal passage of the chips from the pointof cut to the point of discharge, and, moreover, so guide and direct thechips as to compel them to take such course.

In the annexed drawings, Figure l represents in elevation the hollowchisel. Fig. 2 is an end view of the hollow chisel on a larger scale,the end shown being the cutting end. Fig. 3 is an end view of the chiselen the scale adopted in Fig. 2, the end shown being the butt ordischarge end of the chisel. Fig. 4 represents in perspective and on asimilar scale the cutting end of the hollow chisel. Fig. 5 represents alongitudinal central section taken through the chisel shown in Fig. l online 5 5. Fig. 6 is a transverse section ,through said hollow chisel online 6 6 in Fig. 5. Fig. 7 is a view similar to Fig. 2, and shows apreferred form and arrangement of serrations. Fig. S is a like viewwith, however, the entire surface of the wall of the chisel-boreserrated. Fig. 9 is a view corresponding to Fig. 6, but shows the wallof the chisel-bore serrated, so as to provide it with four teethseverally arranged at different points. Fig. lO is a like view, butshows the wall of the bore provided with three sets of serrations. Fig.1l shows a spiral bit substantially proportioned for the size ofchisel-bore shown in Fig. 5. i

The chisel A is provided with a longitudinally-arranged central bore a,which will in practice be linoportioned to the size ot' bit B that is tobe employed in conjunction with the hollow chisel. The cutting end a ofthe chisel is properly sharpened, and is preferably shaped for cutting asquare hole. The cylindric wall of t-he bore a of this chisel isprovided with serrations or teeth a2, which extend along said bore. Thegaps or notches which are formed in the wall of the bore, so as toserrato or provide the same with defined teeth, extend longitudinallyalong said wall; and hence l have herein termed the serrations aslongitudinallyextending serrations, it being seen that each tooth orserration is of a width proportional to the length of each gap or notchwhich is cut into the wall to produce a tooth.

For the purpose of cutting holes the buttend c3 of the chisel is to beheld in a machine suitable fo/r raising and lowering it, which saidmachine will also be adapted for holding the bit and for both rotatingand imparting thereto an end movement, it being understood that thechisel and bit will be so held by the machine that the bit may extenddown through the bore of the chisel.

During operation the bit will bore a round hole in the wood, and whilethe bit is performing such work the machine will cause the chisel tohave an end movement in a direction. to cut away the wood about the holeformed by the bit, and hence squarel the same, it being desirable to cutwith the chisel as rapidly as the bit bores the hole, so that the chipsmay pass up or back through the hollow chisel. The longitudinalserrations within the bore of the hollow chisel effectively prevent thechips from whirling round with the revolving bit and compel them totravel directly back to the upper discharge end of the hollow chisel, itbeing of course understood that the boring tools may be held hori-Zontally or vertically, or at any desired angle. The portions a4 of thewall of the chisel-bore, which in a majority of figures arenon-serrated, are preferably left to so guide and center the bit, itbeing seen that the teeth formed by the longitudinal serrations do notproject within the true radius of the bore, and hence that they do notinterfere with the operation of the bit. the wall of the bore are simplyof sufficient width to provide guiding-surface for the bit, theremaining portion of the bore (and hence a large portion of its surface)being occupied by the serrations, which, being arranged inoppositely-disposed sets, most effectively prevent the tool frombecoming clogged and compel the chips to work back to the discharge endof the hollow chisel.

I nd by-practical experiment that by the foregoing arrangement I amenabled to dispense entirely with the chip discharging slots which haveheretofore been provided through the sides of the hollow7 chisel, andwhich have usually been formed to extend about from line to line y, Fig.l. It will be evident that where the chisel is t-hus provided withchip-discharging slot-s a hole of considerable depth could not be cutwith an ordinary length of chisel, and that to construct the chisel forboring a deep hole the length of chisel from yline an, Fig. l, to thecutting end must be equal to the length of hole to be bored, while, onthe contrary, by my improvement the length of chisel from line i/ to thecutting end need only be equal to the required depth of hole. Itherefore not only shorten up the chisel, but also prevent breakage.

I have not herein illustrated a machine for These non-serrated portionsof.

operating the chisel and bit, since ymachines for operating hollowchisels in conjunction with rotary bits are well known in the art.

I prefer adapting the chisel for cutting square holes, and hence maymake the chisel externally square in cross-section; but I may also makethe chisel externally cylindric for the purpose of boring pump-logs.

In Figs. 2, 3, 4, 5, and 6 I have shown the teeth or serrations madeV-shaped in crosssection, and I may employ to advantage subturns to theright in cutting. lrVhen the chisel is adapted for cutting square holesand is made supercially square in cross-section, the sets of serrationsare advantageously arranged, respectively, op-

posite the several corners of the chisel, for the reason that there willbe more metal at such points; and, moreover, I find in practice thatsuch arrangement is productive of highly-satisfactory result-s, sincethe bore of the chisel will then have oppositely-arranged and longitudinally-extending widths of plain cylindric surface alternating withserrated portions; but good results can be attained by otherwisearranging the serrationsas, for example, I can serrate the entire wallof the bore, as in Fig. 8, the edges of the teeth in such case beingsomewhat blunt, whereby said edges arranged in a circle will serve toguide and center the bit. I can also employ two or more sets ofserrations, as will be understood by reference to Fig. l0, wherein thewall of the chisel-bore is provided with three sets or series ofserrations. I may also serrate the wall of the bore, so as to provide itat each of several points with a single tooth, as in Fig. 9, although ofcourse such arrangement is not nearly so effective as thehereinbefore-described mode of serrating the wall, so as to provide ateach point a plurality of teeth.

`What I claim as myv invention isl. A hollow mortising-chisel for thepurpose described, having the wall of its bore provided withlongitudinally-extending serrations, as set forth.

2. A hollow mortising-chiscl for the purpose described, having the Vwallof its bore composed of longitudinally-extending widths of plaincylindric surface alternating with series of longitudinally-extendingserrations, as set forth.

ALVIN P. LANTERMAN.

Witnesses:

CHAS. G. PAGE, A. CoATEs.

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